Fertilizer



-March 14, 1939.

s. B. Hiv-:ATH ET A.

FERTILIZER Filed Dec. 18,

' TVHJILVH SHUINN'I @EN maf-M Patented Mar, 14, 1939 UNITED STATES2.150.164 Fen'rnmzan/ Sheldon a. nenni ma Jenn w.

The Dow Chemical Oompany, Midland, Mich., a corporation of Michi- Mlch.,assignors to Application December 18,1934, Serial No. '158,133 s china(ci. 'J1-za) Our vinvention relates to the ammoniation ofA fertilizermateriaLparticularly to the ammoniation of wastes, e. g. pulp, remainingafter the f production of sugars, alcohols, etc., 'from sugar cane,beets, corn, etc., which wastes are hereinafter referred vto assaccharinic and amylaceous" wastes, and to the ammoniaticn of otherligneous and celluloslc wastes, e. g. peat, sawdust. corn-stalks, etc.

fertilizer value, and in the caseof starting materials such as straw,peat and others, the material itself before ammoniation is ynot classedas 15 merely bulk but has in itself. 4a beneficial action on the soil.f.

Our starting materials are 'cheap and readily available', and, aftertreatment by our method, may be used as practical fertilizers,particularly 2 where they have a relatively large insoluble nitrogencontent.

When ammoniating materials by prior meth-I' to the total nitrogen in thefertilizer.

A further object of our invention is to provide a process in whichfertilizers may be manufac- 35 -tured that have a high total nitrogencontent.v Y

VYet another'object of our invention is to pro- Y vide a process that iseconomical,.that may be performed with simple apparatus, and which willmake a good fertilizer at low cost. i Still another object of ourinvention is to' provide means for catalyzing the reaction of straw.peat and similar materials with ammonia, so that the fertilizery valueof the material treated is a greatly increased over `that which can beexpected under similar conditions of treat, but in the 'absence of ourcatalysts. v In general our process comprises treatment of va material,such as peat r straw, with ammonia either withl a catalyst which is asalt of an acid,

' preferably an inorganic acid, or with the -acid itself or a mixture ofsalts and acid. Obviously mixtures of salts, orV mixtures of acids, orboth..

may be employed. l

A further method of effecting ammoniation of ture land'becomesammoniated at elevated temy These materials are all solid porous organicmaterials. Y Many ammoniated products have an excellent tilizer, thusenabling the one who uses our fertitemplated. For instance, we have usedwith good 35- action.

than atmospheric.

Corey, Midland,

the material treated is to place the material in contact with anammoniumsalt and allow the; material to soak up the salt in an aqueoussolution for a suillcient period of time to become thoroughlyimpregnated therewith. The impregnated material is then subjected to anelevated temperaperatures. Y

In general we have found that the optimum temperatures in carrying outthis'process lie belo tween 300 C. and 350 C. though good results can beachieved outside of this range, either above cr below it.

In our nitrogenous fertilizers, a high percentage of insoluble nitrogento total nitrogen content is desirable, since nitrogen compounds whichare o but slightly soluble in water (and these are classed` asinsolubles) are slowly available as plant ferlizer material toaccurately determine the necessary dosage for the land, since heavyrains will not tend to greatly change the eifect of a particular dosageapplied. Where fertilizers are of high solubility, heavy rainsoften/wash the fertilizer material onf the land, since they Abecomedissolved in the rain water..v

ASome of the salts which may be used to catalyze the reaction arecalcium chloride, mercuric chloride. zinc chloride, copper sulphate,`sodium acid sulphate, monoor di-sodimn phosphate, ammonium phosphates,etc. The salts may be in some instances employed inL admixture withVacids to catalyseY ammoniation ofthe materials coneffectthe combinationof calcium chloride, an hydrochloric acid as a. catalyalng agent.Another catalvst thatwe have employed is monobasic potassium phosphate(KHnPOi) 'I'herexare a number of other 'salts of acids, o'r acid salts,which can be employed to catalyze the re- 40 While the examples we giveare those of runs made at atmospheric pressure, we do not' wish to b elimited to processes which are conducted at atmospheric pressure only,since the catalysts we provide will eiectively operate at pressuresother In the drawing the single iigureis a table showingthe results ofammoniation carried out in the various runs, the ngures for which aregiven in this specification. y

We will now give some examples of runs which we have made, and theresults which wek have achieved in our process for catalytic ammoniationof amylaceous, 'saccharinia ligneous and cellulosic Wastes.

The following example is one in which we have employed mercuric chlorideas the catalyst. It is to be noted that the percentage of insolublenitrogen to total nitrogen is relatively high.

EXAMPLE No. 1

Ammoniation of straw, using HgCl2 as a catalyst, at 250 C. andatmospheric pressure.

Procedure A mixture of Ychopped straw and HgCl2 (dry,

7.98% H2O) was subjected to a 'stream of NH3A gas at the rate of 430 cc.per minute for 2 hours (which comprised an excess of ammonia, that is tosay more ammonia than the straw would retain). The temperature wasmaintained Vat 250 C.

Results and conclusions Per cent Total N2 10.25 Insol. N2- 8.62 Total N2as insoluble N2 84.09

'I'he use of the catalyst raises the total nitrogen content considerablyhigher than c'an be obtained at the same temperature Without the use ofthe catalyst', and also gives a high percentage of insoluble nitrogen.

Another catalyst that ceedingly useful in this reaction is zincchloride, and the example which follows is one of the process -in whichthis material was used as a catalyst for the ammoniation of straw.

EXAMPLE No. 2

Ammoniation of straw at 285 C. and atmospheric pressure for 2 hoursusing a solution of ZnClz.

Procedure 10.8 grams of straw (dry having 7.98% of H2O) was wetted with10 cc. of a ZnCl2 solution containing 0.190 g. ZnCl2 per cc. 'I'hismixture was heated at 285 C. and NH3 passed therethrough at a rate of430 cc. per minute for 2 hours.

Results and conclusions Total N2 8. 96% Insol. N2 8. 12% Total N2 asinsoluble N2 90. 62% Grams of N2 per gram of original ligneous material.0564 Grams of insoluble N2 per gram of orig.

lig. material 0511 ycatalysts for the ammoniation of the materials ofthe class specified. We have used a number of acids, but we shall giveexamples only of runs made using phosphoric acid, sulphuric acid, andhydrochloric acid. The phosphoric acid in the particular run used wasH2PO4, the orthophosphoric acid.

The following example, No. 3, shows a run in which orthophosphoric acidwas used as the catalyst.

has proved to be ex- EXAMPLE No. 3

Ammoniation of straw, sprayed with an 8.5% solution of phosphoric acid,at 300 C. and atmospheric pressure for 4 hours.

Procedure Approximately 10 g. of straw, (dry, 7.98% H2O) sprayed with 10cc. of an 8.5 solution of HaPO4, was heated at 300 C. for 4 hours atatmospheric pressure, while passing NH2 gas therethrough at a rate of430 cc. per minute.

Results and conclusions Analysis (6.30 g. product) from N2 per cena'- 9.so Insol. N2 per cent-- 8. 60 Total N2 as insoluble N2 per cent-- N2 pergram of original ligneous material gram ,.0617 Insoluble N2 per gram oforiginal ligne ous material gram .0542

'I'he H3P04 acts not only as a catalyst, but the phosphorus is also offertilizer value. It is much cheaper than HgCl2 and furnishes thephosphate which is desirable for a complete fertilizer.

One advantage of the particular catalyst used 'l in theflast run -isthat it is considerably cheaper than mercurio chloride, and also that itfurnishes a constituent in the nal product which has a fertilizer value,i. e., the phosphate.

Very excellent results have been achieved with sulphuric acid. Ingeneral, it has been found that the best results in the catalyticammoniation of the specified materials have been obtained attemperatures between 300 C. and 350 C. Some of our researches haveindicated that optimum results are achieved around the highertemperature limit, namely 350 C. In the following run, Example 4, wehave indicated the use of sulphuric acid at a temperature around 300 C.

EXAMPLE No. 4 v

Ammoniation of peat at 300 C. and atmospheric pressure for two hoursafter the peat, sprayed with dilute sulphuric acid, stood for 18 hours.

Procedure 15 grams of oven-dried peat was sprayed with 20 cc. of diluteH2SO4 (equivalent to 6.43 grams conc. H2804) and allowed to stand. After18 hours, this peat and H2804 were ammoniated at 300 C. and atmosphericpressure for two hours Awith NH2 passed therethrough at the rate of 430cc. per minute.

Results and conclusions Analysis (13.30 grams of product) Total N2 Percent-- 13.60 Insol. N2 Per cent-- 10.50 Total N2 as insoluble N2 Percent-- 77.20 N2 per gram original ligneous v material gram-- .1206Insoluble N2 per gram original ligneous material gram .0931

In the following-example, No. 5, we have shown a run which was made withsulphuric acid at approximately 350 C.

EXAMPLE No. 5

l Ammoniation of straw (dry, 7.98% H2O) using a solution of H2SO4 ascatalyst at 350 C. and atmospheric pressure for two hours. y

Procedure 12 grams of straw was sprayed with 10 cc. oi a 60% solution ofH2SO4 (sp. g., 1.49) and allowed to stand fortwo weeks. 'I'his straw wassubjected to a stream of NH: gas, at the rate of 430A cc. per minute twohours.

Results and conclusions Analysis (7.80 grams product) 'I'here was only asmall amount of ammonium sulphate collected around the cooler part ofthe tube, less than in other runs at lower temperatures. v

To make sure that this insoluble -nitrogen was not due to the largeparticle size of the straw, it was groundvery fine and analyzed again.

Per cent Total N2- y18.12 l Insol. N2 16.52 -1 This materiai was thenwashed with about 25o cc. of water. It was thought that the H2804 mayonly actas liberator for the humic acid and by washing out the H2804 thetotal weight would be decreased with a consequent increase in nitrogen.

This was analyzed and showed 19.37% total N2.'

'Ihe wash water showed a total of 0.13 gram S04 and 0.03 gram N2.

It will be noted -that the total nitrogen is high, and that theinsoluble nitrogen is 89.41% of the total nitrogen. The results of thisrun are very satisfactory.

In the following example, No. 6, we have shown a process employinghydrochloric acid as a catalyst.v

Exlmrtn No.y 6

Ammoniation of straw, using HCI as a catalyst. at 300 C. and atmosphericpressure for about two hours.

Procedure 12 grams of straw (dry, 7.98% H20 was satu-g rated with 18%HCI and allowed to stand for one hour. It was ammoniated by passing overthe straw ammonia gas while gradually raising the temperature to 100 C.for 15 minutes. The passage of ammonia was discontinued and the materialwas heated at 300 C. and atmospheric pressure for 11/2 hours.

Results and conclusions A third method of treatment which we have beforereferred to that gives excellent results, forming a. product having ahigh total nitrogen content and a large percentage of practicallyinsoluble nitrogen, is one in which we employ ammonium sulphate. In thistreat we do not employ any ammonia gas, but obtain the nitriilcation ofthe material by reason of the ammonium radical in the sulphate itself.Other ammonium salts besides ammonium sulphate may be employed, and wedo not wish to be limited in the application of our invention toammonium sulphate alone.

The following run, Example No. 7, shows very excellent results,particularly in view of material costs and also because the process isexceedingly simple, merely requiring heating oi the material, such aspeat, or straw, with the sulphate.

EXAMPLE No. 7

Straw was soaked in a saturated solution of (NH4) 2504 for four days andthen heated at 350 C. for two hours to see if the insoluble N2 contentcould be increased in this manner. f

f Procedure V12 grams of straw (dry, 7.98%.' H20) was soaked in asaturated solution of ammonium sulphate for fourvdays. 'I'he liquid" wasdrained oil and the straw was heatedl for two hours at 350 Results andconclusions Analysis (8.70 grams product) Total N2 percent 15.60 Insol.N2 percent-- 11.12 Total N2 as insoluble N2 percent 71.28 N2 per gram oforiginal ligneous material gram .1131 insoluble N2 per g. originalligneous ma't'eria1 -gram-- .0806

We may also employ other salts besides ammonium sulphate, but, ingeneral, we prefer to employ a salt which has an ammonium radical,

for example ammonium chloride, so that the ammoniation can beaccomplished by reason of' this radical in the salt. `Some forms vnl.'salts are particularly adaptable for this type of process since theyhave not only the ammonium radical,

butalso contain radicals which are available to form a completefertilizer. A substance of this which illustrates a vvery economicalprocess from the point of view of apparatus required and ma terial used,gave a good total yield of nitrogen and a high percentage of insolublenitrogen to total nitrogen. The highest' percent of total nitrogen, aswell as avery high percent of insoluble nitrogen to total nitrogen, isachieved by the process carried out in accordance with VExample No. 5,which, it will be noted, is one employing sulphuric acid as a catalystand a tem- 'I'he nitrication of peat, straw and the like byreacting itat elevated temperatures with am;-

monium salts or with ammonia and ammonium salts' takes place with someloss of .the values therein, such as NH2, or acid radical, or both, in

-the evolved gases, unless said gases are scrubbed for recovery of suchvalues. .In the practical operation of the process the gases evolvedfrom the nitrifying reaction are passed through a wet scrubber tower,the circulating scrubber'solution of which is kept approximately neutralby the addition of ammonia or said acid, as required, so

that it is maintained as an effective absorbent for the values in thegases passing therethrough.

When the scrubber liquor becomes sufclently concentrated, it is used tosaturate peat, straw, etc. entering the nitrifying step, thus making foran eiiicient use of materials.

While We have shown a number of examples and described several alternateforms of our invention, it is to be understood that we are only to belimited by the scope of the appended claims and the showing of the priorart.

We claim:

1. In a method of making a fertilizer, the step which consists inheating a solid'porous organic material to a temperature above 250 C.with ammonia. and a strong mineral acid.

2. In a method of making a fertilizer, the step which consists inheating a mixture of a solid porous organic material and an ammoniumsalt of a strong inorganic acid to a temperature above 250 C.

3. In a method of makinga fertilizer, the step which consists in passingammonia gas at substantially atmospheric pressure through a mixture of asolid porous organic material and a.

strong mineral acid while heating the mixture to a temperature above 250C.

4. In a method of making a, fertilizer, the step which consists inheating peat to a temperature above 250 C. with ammonia in the presenceof a strong mineral acid.

5. In a method of making a fertilizer, the step which consists inheating a mixture of peat and an'ammonium salt of a strong mineral acidto a temperature of at least 250 C. at atmospheric pressure.

6. In a method of making a fertilizer, the step which consists invheating a mixture of peat and ammonium sulphate to a temperature of atleast 250 C. at atmospheric pressure.

7. In a method of making a. fertilizer, the step which consists inheating straw to a temperature above 250 C. with ammonia in the presenceof a strong mineral acid.

8. In a method of making a fertilizer, the step which consists inheating a mixture of straw and ammonium sulphate to a temperature of atleast 250 C. at atmospheric pressure.

JOHN W. COREY. SHELDON B. HEATH.

